fix(landing): correct topo maps layer ID BM-1408 (#3547)

## Motivation

Currently, both our `gridded` and `gridless` basemaps provide the same
API keys, which point to the `gridless` tiles. The `gridded` basemap
should instead reference its own tile source.

## Context

This issue stems from a misconfiguration in the default layer settings
for the `gridded` (Topo Maps) basemap.

| Pattern | Example | Topo Maps |
| - | - | - |
| `<layer_id>::<style_id>` | `topographic-v2::topolite-v2` |
`topo-raster::topo-raster-gridded` |

If the `style_id` is provided, our web application uses that, rather
than the `layer_id`, to fetch the desired imagery (tileset). This is
what happens with the `gridded` basemap. That said, our application uses
the `layer_id` value to generate the API keys. Hence why the imagery is
correct but the links are wrong.

## Modifications

- **packages/landing/src/`config.map.ts`**

  - Fixed the Topo Maps default layer's `id` value.

    | Before | After |
    | - | - |
| `topo-raster::topo-raster-gridded` |
`topo-raster-gridded::topo-raster-gridded` |

## Verification

### Screenshots

| Topo Maps | Topo Gridless Maps |
| - | - |
| `i=topo-raster-gridded&style=topo-raster-gridded` |
`i=topo-raster&style=topo-raster` |
| ![][topo-maps-img] | ![][topo-gridless-maps-img] |

### API Keys

- **Topo Maps**

  - **WMTS: NZTM2000Quad**
    ```
    /v1/tiles/topo-raster-gridded/NZTM2000Quad/WMTSCapabilities.xml
    ```

  - **WMTS: WebMercatorQuad**
    ```
    /v1/tiles/topo-raster-gridded/WebMercatorQuad/WMTSCapabilities.xml
    ```

  - **xyz**
    ```
    /v1/tiles/topo-raster-gridded/WebMercatorQuad/{z}/{x}/{y}.webp
    ```

- **Topo Gridless Maps**

  - **WMTS: NZTM2000Quad**
    ```
    /v1/tiles/topo-raster/NZTM2000Quad/WMTSCapabilities.xml
    ```

  - **WMTS: WebMercatorQuad**
    ```
    /v1/tiles/topo-raster/WebMercatorQuad/WMTSCapabilities.xml
    ```

  - **xyz**
    ```
    /v1/tiles/topo-raster/WebMercatorQuad/{z}/{x}/{y}.webp
    ```

[topo-maps-img]:
https://github.com/user-attachments/assets/7a48ea1d-e68d-497f-b950-ae6e4fed4948
[topo-gridless-maps-img]:
https://github.com/user-attachments/assets/1f8114d5-0d7c-47d2-ac81-3fca4f301bfb

Author: tawera-manaena

packages/landing/src/config.map.ts

@@ -395,7 +395,7 @@ function addDefaultLayers(output: Map<string, LayerInfo>): void {
       category: 'Basemaps',
     },
     {
-      id: 'topo-raster::topo-raster-gridded',
+      id: 'topo-raster-gridded::topo-raster-gridded',
       title: 'Topo Maps',
       projections: new Set([EpsgCode.Nztm2000, EpsgCode.Google]),
       category: 'Basemaps',